1. Field of the Invention
The present invention relates to an antenna, and particularly to a dual-frequency directional antenna.
2. Description of Related Art
Nowadays, following the advancement of integrate circuits, wireless communication apparatuses have been developed to be light and thin. Plane antennas, manufactured with printing circuit method, are highly integrated and advantageous such as easy to be integrated with peripheral elements, thus become the mainstream in the telecommunication market. However, after those conventional antennas being miniaturized, it is inevitable that the frequency bandwidth is narrowed down and the radiation efficiency is reduced, which relatively limits the emitting and receiving of signals, and as a result affects the communication quality. Therefore, how to broaden the operation frequency, satisfy the requirement for multi-frequency signal emitting and receiving and miniaturize the antenna becomes an important issue when designing antennas.